The present invention relates to an image display method and ultrasonic diagnostic apparatus, and more particularly to an image display method and ultrasonic diagnostic apparatus which ensures that an image having been displayed at the time of release of freeze can be re-displayed even after the release of the freeze.
A conventional ultrasonic diagnostic apparatus has a normal display mode and a cine display mode.
In the normal display mode, a subject is scanned to obtain successive images which are displayed in real-time. The oldest image stored in a memory is overwritten with the newest image, and data sets for a plurality of the newest images are thus stored in the memory.
In the cine display mode, deletion by the overwriting is stopped, and the plurality of images stored in the memory is sequentially displayed in time order. If a human operator commands freeze during the cine display, the sequential display is suspended, and the image displayed at that time is continuously displayed. If the operator commands rewind during the freeze, the images are traced in inverse time order from the image currently displayed, and when the operator stops the rewind, an image reached at that time is displayed. If the operator commands save of the image, the image displayed at that time is saved. Since that image will not be overwritten or deleted even when the freeze is released to return to the normal display mode, the saved image can be recalled for display any time the operator commands recall.
However, according to the conventional ultrasonic diagnostic apparatus, images other than an image which is specified to be saved are lost from the memory by the overwriting deletion. Thus, such apparatus involves a problem that if the operator inadvertently misses the command to save a necessary image before releasing the freeze, the necessary image is lost and hence re-scanning is required.